1. Field of the Invention
The present invention relates to delineator poles that may be used for delineating boundaries in different applications. Specifically, the present invention relates to an anchoring base and spring cartridge for self-aligning, pivotable delineator poles used in snow sports, and more specifically to self-aligning, pivotable delineator poles for ski racing applications, and for temporary or movable markings, netting, or barriers for trail safety applications.
2. Description of Related Art
Many different types of pivotable delineator poles for snow-based applications are used for such things as slalom gates or hazard markers, to name a few. Delineating poles are often damaged or cause damage when a moving object comes into contact with the pole. Ski racing, for example, involves full contact between skiers traveling at high velocities and slalom poles resulting in damage to the poles and, in many instances, harm to the skiers.
Poles used in ski racing to delineate the racecourse are called alternatively slalom gates or simply gates. As depicted in FIG. 1, a typical slalom gate or pole 10 is generally constructed of three major components: 1) a shaft 12, which is typically hollow and made of plastic; 2) a spring cartridge or mechanism 14 used for pole bending; and 3) ground engagement means or anchoring base 16. Generally, shaft 12 is a simple, hollow, rigid plastic tube that provides the function of delineating a physical location in a highly visible manner. Spring cartridge or mechanism 14 slides into the bottom of shaft 12 and is fixably attached to shaft 12. Similarly, on its opposite end, spring cartridge 14 slides into anchoring base 16 and is fixably attached thereto as well.
Spring cartridge 14 is typically constructed as depicted in FIG. 2. A flexible polymer tendon 22 performs the bending function for the pole to respond to the impact force supplied by a skier. Springs 24 provide the restoring force to return or self-align the gate in the vertical position. Tendon 22 is protected by a series of superposed annular members such as external collars or rings 26. Rings 26 are typically circularly symmetric and donut-shaped, made from a hard nylon material or the like. Tendon 22 cooperates with springs 24 and rings 26 to promote the flexible bending and restoration of the pole segments relative to one another. Rings 26 also provide leverage for tendon 22 during flexing or bending, and are used as a “stop” to define the vertical rest position of the gate.
During bending, rings 26 assume angular positions along the curvature of the bent surface of slalom gate 10. Rings 26 provide for a flexible bend radius of flexure for slalom gate 10, thereby minimizing the danger of breakage of slalom gate 10 due to over bending and to reduce the chances of injury to the skier. Rings 26 also serve to keep out dirt and snow from normally entering the pole.
One such structure is identified in U.S. Pat. No. 4,588,324, issued to Goellner, entitled “SLALOM POLE.” Goellner discloses a delineating pole which is supported by a lower part placed in the ground, and an upper part which is made to pivot against the lower part when subjected to an impact force. In the Goellner design, the upper, middle, and lower portions of the pole are held together in tension by a sprung axial cable. The upper and lower portions each include a respective spring. The tension spring cooperates with collars to provide for a flexible bending radius of flexure of the pole.
Another approach is taught in U.S. Pat. No. 4,270,873 issued to Laehy, et al., entitled “PIVOTABLE DELINEATOR POST.” The Laehy pole includes upper and lower segments with a biasing spring completely housed within the lower pole segment. The upper and lower pole segments are joined by the spring and are held in axial alignment by the mating cooperation of a rounded edge lip portion adjacent the lower pole segment and a rounded groove flange adjacent the upper pole segment. Whenever the upper and lower pole segments are moved out of axial alignment, the force of the spring together with the rounded edge lip portion and the groove of the flange interact to guide the segments back into axial alignment.
The form of current slalom gates has so developed in order to provide certain desirable functions. First, the gate must define a particular point on the slope in a highly visible manner. Second, as the ski racer strikes the slalom gate, the pole must move quickly to the skier's impact force while remaining securely anchored in the snow. Third, the pole must, after responding to the skier's impact force, return to its original vertical position, thereby re-aligning itself. The three major components of the slalom gate discussed above work together to provide these functions.
Slalom poles are usually anchored in a layer of snow or ice on a ski slope, commonly referred to as a snow pack. In most cases the anchoring is made by drilling a hole in the packed snow or ice, whereupon the pole or an anchoring device connected to the pole is fixed in the snow pack. It is desirable for the slalom pole to be fixable in and removable from the snow pack in a quick and easy manner. At the same time, the slalom pole fixed in the snow pack must be held in a stable manner even when subjected to impacts and blows from the skier.
Referring to FIG. 1, the anchoring base 16 is typically a plastic shaft approximately thirteen (13) inches in length and having large, coarse threads 18 for forming a screw-shaped operating rod with a conical end. Anchoring base 16 is screwed into a pre-drilled hole in the snow. In order to secure anchoring base 16 in the snow, the slalom pole is fitted with external wrench engaging means to mate with a specialized wrench. The wrench engaging means is adapted to be engaged by a specialized wrench (not shown) in order to rotate slalom gate 10 about its longitudinal axis. This rotation permits coarse threads 18 to thread the snow pack, which seats slalom pole 10 in the snow. The purpose of coarse threads 18 on anchoring base 16 is simply to secure the slalom pole within the snow upon rotation. A user cannot simply push the slalom pole with threads on its anchoring base into the hole, or pull the slalom pole with threads on its anchoring base out of the hole, without performing a number of rotations. Furthermore, currently available slalom poles without threads do not provide for sufficiently secure anchors to allow them to remain in place when impacted by a skier.
As it is advantageous for a ski race to be held on packed snow, it is commonplace for the snow to be very hard, dense, and icy in the vicinity of the racecourse, and most likely where the gates must be installed. In fact, often various means are employed to facilitate installation of the gates, such as salting or injecting water to make the snow surface harder and more resistant to wear during the race.
The anchoring device takes a long time to screw it in position, as well as to unscrew it. As such, setting a course, even for simple training exercises, is timely and labor intensive. Generally, using prior art slalom poles, three people are required to set a racing course: one to drill a hole, a second to carry and supply the slalom poles, and a third to rotate the anchoring base. Furthermore, when screwing an anchoring base into a hard snow pack, a substantial amount of torque is required at the anchoring base since spring cartridges of the prior art cannot withstand the rotational extraction force. Thus, the insertion and operation of the specialized wrench requires an operator to stoop down or bend on the slope in an unnatural position for a lengthy insertion and extraction process, which can cause physical exertion.